Paris - Toulouse outpowered Agen 52-19 in a eight-try mauling to edge ever closer to a berth in the Top 14 play-offs on Sunday.
Ugo Mola's Toulouse now sit on 66 points in fifth spot, two behind both Toulon and Racing 92 and five ahead of Bordeaux, with only the top six heading into the play-offs.
For Agen, however, the result meant they joined Oyonnax in relegation to the ProD2, France's second division, with three games of the season still to play.
In a free-running contest in blustery conditions at the Stade Ernest-Wallon, Toulouse built up a comfortable 33-7 lead by half-time.
France international trio Sebastien Bezy, centre Gael Fickou and veteran winger Vincent Clerc all crossed for tries in the first 22 minutes before Agen's South African back Johann Sadie pulled one back for the visitors.
Louis Picamoles guaranteed Toulouse a bonus point with the team's fourth, swiftly followed by Fickou going over for his second.
All Black hooker Corey Flynn crossed for Toulouse's sixth, while Tamaz Mchedlidze pulled one back for an Agen side that refused to lie down.
Gilian Galan, on as a replacement for Picamoles, enjoyed a barn-storming cameo display, barging his way over for a brace of late tries, punctuated by one for Agen's Fijian winger Leka Tagotago.
But it was all too late for Agen, who remain bottom of the Top 14 and were confirmed for relegation for the third time in the professional era after similar returns to the ProD2 in 2007 and 2013.
Castres travel to Toulon in Sunday's late game, the former seeking to move into sixth spot and the latter to edge closer to second-placed Montpellier.
On Saturday, leaders Clermont made sure of their spot in the play-offs with a hard-fought 16-10 victory over Pau.
The victory left Clermont on 79 points, six ahead of Montpellier, who play Harlequins in the European Challenge Cup final in Lyon on Friday, but whose largely second-string side went down 36-10 at La Rochelle.
Big-spending Racing 92, who face Saracens in the European Cup final next Saturday, also rested their big guns and went down to a 33-27 loss to Brive. Despite the defeat, Racing maintain fourth place in the table.
Defending champions Stade Francais allayed relegation fears with a 10-try 69-8 rout of Oyonnax, a result which confirmed that the Parisians remain in the Top 14 but that the latter club drop down to the ProD2.
In Friday's game, Bordeaux-Begles defeated Grenoble 20-14.